I wanted to try my hand at used PC building, and my Fiance needed something besides her laptop, I feel like I spent a little too much on everything, but it still came out not bad.
I'm still waiting for new CPU cooler, I used the stock cooler to make sure everything worked, and posted after setting everything up.

Base system with 8GB DDR2 and 500GB HDD $80
120GB SSD, I had this laying around
New PSU $50
CPU + Adapter Sticker $31 (Intel Xeon X5482)
2.5" to 3.5" Adapter $5
New CPU Cooler $35 (The CPU TDP is 150w, I bought a Enermax ETS-T40F, which is rated for 200w)
GPU rx570 4gb: $75
New CMOS Battery

It came with an okay(Cooler Master brand) PSU, but only 500w, which is the minimum recommended for rx570, I wanted to give the GPU and CPU some breathing room, and PSU calculator suggested at least 550w, so I bought a new 650w
I feel like I could have saved money hunting for a used PSU, and a used CPU cooler.
Looking on YouTube, this Xeon CPU still seems very capable, and better than the Intel Core2 Duo E6850 the computer came with, might end up bottle necking the GPU, I haven't run any benchmarks yet waiting for the new CPU cooler.
I feel the DDR2 will end up holding this back as well, but it should still do a good enough job, until we save enough money to build a new gaming computer.